Bluetooth: controller: Add Direction Finding specific KConfig

Add separated Kconfig file for Bluetooth 5.1 Direction Finding.
Enable controller support for:
 - transmission of CTE
 - 2us antenna switching
 - 1us antenna switching
if build for nRF52833 SOC.
Add HAS_HW_NRF_RADIO_BLE_DF to nrf52833 SOC configuration.

Signed-off-by: Piotr Pryga <piotr.pryga@nordicsemi.no>

soc/arm/nordic_nrf/Kconfig.peripherals

@@ -124,6 +124,9 @@ config HAS_HW_NRF_RADIO_BLE_CODED
 config HAS_HW_NRF_RADIO_IEEE802154
 	bool
 
+config HAS_HW_NRF_RADIO_BLE_DF
+	bool
+
 config HAS_HW_NRF_RNG
 	bool
 

soc/arm/nordic_nrf/nrf52/Kconfig.soc

@@ -295,6 +295,7 @@ config SOC_NRF52833
 	select HAS_HW_NRF_RADIO_TX_PWR_HIGH
 	select HAS_HW_NRF_RADIO_BLE_CODED
 	select HAS_HW_NRF_RADIO_IEEE802154
+	select HAS_HW_NRF_RADIO_BLE_DF
 	select HAS_HW_NRF_RNG
 	select HAS_HW_NRF_RTC0
 	select HAS_HW_NRF_RTC1

subsys/bluetooth/controller/Kconfig

@@ -550,6 +550,7 @@ config BT_CTLR_SMI_TX_SETTING
 	help
 	  Enable support for Bluetooth 5.0 SMI TX through a system setting.
 
+source "subsys/bluetooth/controller/Kconfig.df"
 source "subsys/bluetooth/controller/Kconfig.ll_sw_split"
 
 config BT_CTLR_ASSERT_HANDLER
@@ -561,11 +562,6 @@ config BT_CTLR_ASSERT_HANDLER
 	  and will be invoked whenever the controller code encounters
 	  an unrecoverable error.
 
-config BT_CTLR_DF
-	bool "LE Direction Finding Support [EXPERIMENTAL]" if BT_LL_SW_SPLIT
-	help
-	  Enable support for Bluetooth 5.1 Direction Finding
-
 endif # BT_CTLR
 
 config BT_CTLR_DEBUG_PINS_CPUAPP

subsys/bluetooth/controller/Kconfig.df

@@ -0,0 +1,64 @@
+# Zephyr Bluetooth Controller configuration options
+
+# Copyright (c) 2020 Nordic Semiconductor ASA
+# SPDX-License-Identifier: Apache-2.0
+
+config BT_CTLR_DF_SUPPORT
+	bool
+
+config BT_CTLR_DF_CTE_TX_SUPPORT
+	bool
+
+config BT_CTLR_DF_ANT_SWITCH_2US_SUPPORT
+	bool
+
+config BT_CTLR_DF_ANT_SWITCH_1US_SUPPORT
+	bool
+
+menuconfig BT_CTLR_DF
+	bool "LE Direction Finding [Experimental]"
+	depends on BT_CTLR_DF_SUPPORT
+	help
+	  Enable support for Bluetooth 5.1 Direction Finding
+
+if BT_CTLR_DF
+
+# Basic controller functionalities required for implementation of
+# Bluetooth v5.1 Direction Finding
+
+config BT_CTLR_DF_CTE_TX
+	bool "Enable transmission of Constant Tone Extension"
+	depends on BT_CTLR_DF_CTE_TX_SUPPORT
+	default y
+	help
+	  Enable support for transmission of Constant Tone Extension in
+	  controller.
+
+config BT_CTLR_DF_ANT_SWITCHING_1US
+	bool "Enable support for 1us antenna switching slots"
+	depends on BT_CTLR_DF_ANT_SWITCH_1US_SUPPORT
+	default y
+	help
+	  Enable support for 1us antenna switching slots. This antenna switching
+	  mode is optional for Direction Finding according to Bluetooth v5.1.
+
+# Features related with Direction Finding
+# BT Core spec 5.1, Vol 6, Part B, sec. 4.6 Feature Support
+
+config BT_CTLR_DF_ANT_SWITCH_TX
+	bool "Enable antenna switching during CTE transmission (AoD) feature"
+	depends on BT_CTLR_DF_CTE_TX && BT_CTLR_DF_ANT_SWITCH_2US_SUPPORT
+	default y
+	help
+	  Enable support for antenna switching during CTE transmission.
+	  Also known as Angle of Departure mode.
+
+config BT_CTLR_DF_CONN_CTE_RSP
+	bool "Enable Connection CTE Response feature"
+	depends on BT_CTLR_DF_CTE_TX && BT_CONN
+	default y
+	help
+	  Enable support for Bluetooth v5.1 Connection CTE Response feature
+	  in controller.
+
+endif # BT_CTRL_DIRECTION_FINDING

subsys/bluetooth/controller/Kconfig.ll_sw_split

@@ -37,6 +37,13 @@ config BT_LLL_VENDOR_NORDIC
 	select BT_CTLR_XTAL_ADVANCED_SUPPORT
 	select BT_CTLR_SCHED_ADVANCED_SUPPORT
 	select BT_CTLR_TIFS_HW_SUPPORT
+	# Direction Finding
+	select BT_CTLR_DF_SUPPORT if HAS_HW_NRF_RADIO_BLE_DF
+	select BT_CTLR_DF_CTE_TX_SUPPORT if HAS_HW_NRF_RADIO_BLE_DF
+	select BT_CTLR_DF_ANT_SWITCH_2US_SUPPORT if HAS_HW_NRF_RADIO_BLE_DF
+	# optional ant switching slot mode
+	select BT_CTLR_DF_ANT_SWITCH_1US_SUPPORT if HAS_HW_NRF_RADIO_BLE_DF
+
 	default y
 	help
 	  Use Nordic Lower Link Layer implementation.